Nice atmosphere. The lighting looks good. Add trims to the pipes where they join the wall and add some kind of support from the ceiling for them. I think the pool is a bit out of place but it looks interesting. I mean carpets, wood, marble, what is this place? As far as I know it's part of Black Mesa, but why would it need to be so pretty and expensive? I also think a few couches, trash cans and a wending machine would fit in there.
EDIT: Also I think the bright wooden floor texture is a bit too bright and clean. I mean people are walking on it and Black Mesa is a pretty old place. Anyway just make the texture a bit darker and bit more dirty with some small scratches or something. There could be a bit more contrast among the planks too.